Blockchain is a fairly new technology and still in its infancy. As a result, many research papers are creating optimized consensus algorithms. Therefore, a need for key characteristics to create optimized blockchain consensus algorithms has been identified. This research paper presents the results of a systematic literature on identifying the main blockchain consensus algorithms and their associated advantages and disadvantages. Papers from four different databases were retrieved and after exclusion criteria were applied, 44 papers were ultimately included in the review. Results indicated that the five main consensus algorithms were Proof-of-Work (PoW), Proof-of-Stake (PoS), Practical Byzantine Fault Tolerance (PBFT), and Delegated Proof-of-Stake. The results further indicated that efficiency was the main advantage of the PoS, PBFT, PoA and hybrid consensus algorithms. The main disadvantage was “energy wastage” and was attributed to the PoW algorithm. Security concerns were the main disadvantage of the PoS algorithm. These findings were used to present key characteristics that future researchers can have in mind when creating optimized blockchain consensus algorithms.